1. Field of the Invention
This invention relates to a method for selecting an optimum type of containers for packaging component parts of vehicles, for example.
2. Description of the Related Art
Component parts, and the like, of vehicles were usually contained in corrugated containers, and specific parts were sometimes contained in semipermanently durable containers.
Corrugated containers are disposable containers that are used only once and disposed thereafter, and annual expense for corrugated containers is fixed in accordance with annual demand of component parts. Therefore, as far as corrugated containers are used, improvement of commercial profit is not expected.
On the other hand, semipermanently durable containers are expensive. Nevertheless, if component parts themselves are changed in shape due to a model change, for example, such durable containers will become unusable and will result in being uneconomical.
For some kinds of component parts, the use of containers durable over a certain number of repetitive use may become economical in a long run even though their unit cost is higher than corrugated containers. Additionally, when a possible change of the shape of component parts is taken into consideration, such containers may be economical than semipermanently durable containers.
It is therefore an object of the invention to provide a method for selecting a container model for component parts, capable of selecting a most profitable, optimum container model for a particular item of component parts.
According to the invention, there is provided a method for selecting a container for component parts comprising the steps of:
setting a prototype container unit price, a per-unit container recovery expense, an annual purchase frequency, a durable period and an annual demand quantity for each of various container models other than a disposable container model for a specific component part;
in case that said container has a durable period shorter than one year,
calculating the annual container purchase expense on the basis of the annual demand quantity, the annual purchase frequency and the prototype container unit price;
calculating an annual container recovery expense on the basis of said annual demand quantity, the container recovery expense and the annual purchase frequency thereof; and
calculating a total expense of the container having a durable period shorter than one year in predetermined years on the basis of the annual container purchase expense and said annual container recovery expense thereof,
in case that the container has a durable period not shorter than one year;
calculating an initial-year container purchase expense on the basis of the annual demand quantity and the prototype container unit price thereof;
calculating a next-year container purchase expense on the basis of the annual demand quantity, the prototype container unit price and an annual supplementary rate thereof;
calculating the annual container recovery expense on the basis of the annual demand quantity and the container recovery expense; and
calculating a total expense in the predetermined years of the container having a durable period not shorter than one year on the basis of the initial-year container purchase expense, the next-year container purchase expense and the annual container recovery expense;
repeating calculation of total expenses of the others of the container models; and
selecting optimum one of the container models having the least total expenses in the predetermined years among calculated the total expenses in the predetermined years and the total expense in the predetermined years of the disposable container.
This method enables computation of the total expenses in predetermined years of various container models other than disposable container models such that a most economical, optimum container model can be selected by comparing the total expenses in predetermined years including those of disposable containers.
Therefore, by comparing the total expenses in predetermined years, it is possible to find out a container model more commercially profitable than disposable containers and more economical than semipermanently durable containers.
The computation may result in indicating a disposable container as the most inexpensive, optimum container model for a particular part.
In the method for selecting a container model for component parts, the component parts to be contained in the container may be a vehicle component parts, and the predetermined years may be six years from the first to sixth years.
Vehicles are usually changed in model every three to four years. According to the past data, operation attenuation rates of vehicle component parts tend to rapidly drop as from the fifth year. Therefore, expenses required for containers from the first year, where new component parts are first purchased, to the sixth year, which is next to the year where their operation attenuation rates begin to rapidly lower, indicate most actual expenses of containers of vehicle components parts.
In the method for selecting a container model for component parts, the annual supplementary rate is preferably 0.03. More specifically, in case of a container model whose life exceeds one year, it is reasonable in view of the average of the past records to determine that the annual supplementary rate that indicates the rate of supplementation required by the next year due to breakage and others is 0.03 (3%).